Secondary lip for scrapers

ABSTRACT

In a scraper excavating apparatus, the secondary lip comprises an apron skirt which is coextensive in width with, and is of sustantially similar curvature as, the apron of the scraper; guideways which are fastened at each side of the apron and which are operable to guide vertical travel of the skirt over the lower portion of the forward, exterior side of the apron; and a suitable actuator, such as cables, to selectively raise and lower the apron skirt with respect to the apron and to selectively dispose the lowermost terminal edge of the apron skirt contiguously adjacent the uppermost side of the scraper cutting bit.

United States Patent [191 Bronson et a1.

SECONDARY LIP FOR SCRAPERS Inventors: Orville P. Bronson, 5209 Targee,

Space No. 14, Boise, Idaho 83705; Bruce L. Crabtree, Sr., PO. Box 423, Snohomish, Wash. 98290 Filed: Mar. 12, 1973 Appl. No.: 340,624

Related U.S. Application Data Continuation-in-part of Ser. No 234,361, March 13, 1972.

References Cited UNITED STATES PATENTS Daniels 37/126 R Hyler 37/126 AB [451 Dec. 25, 1973 Primary ExaminerRobert E. Pulfrey Assistant ExaminerEugene H. Eickholt Attorney-John W. Kraft [57] ABSTRACT In a scraper excavating apparatus, the secondary lip comprises an apron skirt which is coextensive in width with, and is of sustantially similar curvature as, the apron of the scraper; guideways which are fastened at each side of the apron and which are operable to guide vertical travel of the skirt over the lower portion of the forward, exterior side of the apron; and a suitable actuator, such as cables, to selectively raise and lower the apron skirt with respect to the apron and to selectively dispose the lowermost terminal edge of the apron skirt contiguously adjacent the uppermost side of the scraper cutting bit.

3 Claims, 2 Drawing Figures 1 SECONDARY LIP FOR SCRAPERS REFERENCE TO OTHER APPLICATION This is a continuation-in-part application of copending application of Orville P. Bronson and Bruce L. Crabtree for Utilization of a Secondary Lip for Construction Scraper "Equipment, Ser. No. 234,361, filed on Mar. 13, l972.

FIELD OF INVENTION The present invention relates to excavating apparatus and more particularly to a secondary lip for the apron of a scraper excavator.

DESCRIPTION OF THE PRIOR ART Wheel scrapers refer to various heavy equipment vehicles which include a towed box or bowl hung on a wheel frame to cut material by means of a planing bit or blade in the bottom of the bowl, to accumulate material in the bowl, and to eject material from the bowl. As shall be described at length hereinafter, the bowl cuts and accumulates material by means of the bit at the open forward end of the bowl, and retains the accumulated material during transport by means of a pivotally carried wall or apron which may be raised or lowered to open or close the forward end of the bowl. A'n apparent and notorious problem is that the apron and the bit may not mate because debris becomes lodged between the apron and the bit. Various attempts have been made to remedy this situation, including providing an openwork apron, but none have been commercially successful because material still becomes lodged between the apron and the bit.

Accordingly, it is an object of the present invention to provide means for closing the forward portion 'of a scraper, despite debris which might be lodged between the apron and the cutting bit of the scraper.

It is a further object that the aforesaid closure means be carried and actuated so as not to impair the conventional mode of operation of the scraper apron.

It is a another object that the aforesaid means be provided with an actuator which may be selectively controllable over the travel of the closure means with re spect to the apron.

These and other objects shall become apparent from the description following, it being understood that modifications may be made without affecting the teachings of the invention here set out.

SUMMARY OF THE INVENTION In a scraper excavating apparatus, the secondary lip generally comprises an apron skirt which is coextensive in width with, and is of substantially similar curvature as, the apron of the scraper; guideways which are fastened at each side of the apron and which are operable to guide vertical'travel of the skirt over the lower portion of the forward, exterior side of the apron; and a suitable actuator, such as cables, to selectively raise and lower the apron skirt with respect to the apron and to selectively dispose the lowermost terminal edge of the apron skirt contiguously adjacent the uppermost side of the scraper cutting bit. The secondary lip may be actuated by an hydraulic cylinder, or by cable-type lifters.

A more thorough and comprehensive understanding may be had from the detailed description of the preferred embodiment when read in connection with the drawings forming a part of this specification.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a right side elevational view of a wheel tractor scraper of this invention with a portion of the scrapers side wall broken away showing to advantage the secondary lip of this invention and its apron, both being in their up positions.

FIG. 2 is a fragmentary right side elevational view of the apparatus of the FIG. 1, drawn to a larger scale with a portion of the scrapers side wall broken away showing to advantage the secondary lip in its down position and the apron in its closed position, and showing a debris-obstruction lodged between the apron and the cutting edge for illustrative purposes.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings and more particularly to the FIG. 1, the secondary lip for scrapers of the present invention is shown to advantage and generally identified by the numeral 10. The secondary lip 10 is mounted to, and facilitates the operation of, a scrapertype excavator, such as a wheeled tractor scraper 11. It is to be understood that, although a wheeled tractor scraper 11 is shown and described, a variety of scraper apparatus may be provided advantageously with the secondary lip 10.

A bowl 12 is the most relevant portion of the scraper 11 to the secondary lip 10. The bowl 12 is a materialcarrying enclosure open from above and to its forwardmost terminal end. The bowl 12 comprises a base or planing wall 13, a pair of substantially parallel, upsta'ndingly disposed, side walls 14 issuing from each side of the planing wall 13, and a rear or ejector wall 15 issuing upwardly from the rearwardmost terminal end of theplaning wall 13 and the side walls 14. The planing wall 13 is typically inclined downwardly from its rea'rwardmost terminal end to its forwardmost end to facilitate accumulation of material in the bowl 12. The forwardmost, leading edge of the planing wall 13 is provided with a downwardly inclined cutting bit 16. The cutting bit 16 is operable to break, collect and direct material onto the planing wall 13 and into the bowl 12. The forwardmost, open end of the bowl 12 is selectively enclosed by an apron 17.

As shown more clearly in the FIG. 2, the apron 17 is a pivotally mounted wall 17' carried on arms 18 which are pivotally fastened distally from the forwardmost terminal end of each of the side walls 14. It has been found to advantage to pivot the arms 18 on the side walls 14 above the cutting bit 16 to swing substantially upwardly when opened, rather than forwardly. This tends to reduce the natural bulldozer affect of the apron 17. The apron 17 is selectively raised and lowered by an actuator, such as suitably actuated cables 19. The apron 17 may also be actuated by hydraulic cylinders and the like. The apron 17 is typically configured and mounted to juxtaposition the lowermost terminal edge of the apron 17 on the forward portion of the uppermost terminal side of the cutting bit 16. This is done by design to reduce the aforementioned bulldozer affect of the apron l7 and to permit accumulation of material at short openings of the apron 17. It may be seen that this configuration is highly prone to lodge debris 20 between the lowermost terminal edge of the apron 17 and the bit 16. This may result in loss of material from the bowl 12, or a ragged cut.

The secondary lip comprises an apron skirt 21, guideways 22, and an actuator cable 23. The apron skirt 21 is a wall-like member which is coextensive in width with, and following substantially the same curvature as, the apron wall 17. The apron skirt 21 rides over and is frictionlessly carried by the lower portion of the forward or exterior side of the apron wall 17 on guideways 22. The guideways 22 are fastened at each side of the apron 17, and are operable to guide the travel of the lowermost terminal edge of the apron skirt 21 distally below and distally above the lowermost terminal edge of the apron wall 17. The apron skirt 21 may be selectively raised and lowered by any of a variety of actuators actuating the cable 23. The cable 23 may be actuated through suitable pulleys 24 by a winch (not shown) mounted on the tractor portion of the scraper 11, or on the bowl 12. The cable 23 is fastened to the uppermost terminal edge of the apron skirt 21 by means of a shackle 25. It is to be understood that the skirt 21 may also be actuated by a suitable power pressure cylinder mounted to the apron 17 and the skirt 21.

The secondary lip 10 may be raised to an open, accumulating position by the cable 23, and the apron 17 may be operated in the conventional way. The bowl 12 may be closed, again in the conventional way, by lowering the apron l7, regardless of whether or not debris is lodged between the apron 17 and the bit 16. Closure of the forward end of the bowl 12 may be ensured by lowering the apron skirt 21 of the lip 10 with respect to the apron wall 17' to be contiguously adjacent the uppermost side of the cutting bit 16. The bowl 12 may be reopened by again raising the lip 10 with respect to the apron 17 and raising the apron 17 with respect to the cutting bit l6.

Having thus described in detail a preferred apparatus which embodies the concepts and principles of the invention and which accomplishes the various objects, purposes and aims thereof, it is to be appreciated and will be apparent to those skilled in the art that many physical changes could be made in the apparatus without altering the inventive concepts and principles embodied therein. Hence, it is intended that the scope of the invention be limited only to the extent indicated in the appended claims.

We claim:

1. In combination with a scraper excavating apparatus including a bowl having a cutting bit at the forwardmost terminal edge of its base wall and a suitably, vertically actuated apron, a secondary lip, comprising:

an apron skirt being coextensive in width with and or substantially similar curvature as said scraper apron;

guideways fastened at each side of said scraper apron to guide vertical travel of said apron skirt over the lower portion of the forward, exterior side of said apron; and

an actuator means for selectively raising and lowering said apron skirt with respect to said apron, to dispose the lowermost terminal edge of said apron substantially, contiguously adjacent the uppermost side of said scraper cutting bit.

2. The apparatus of claim 1 wherein said actuator means for selectively raising and lowering said apron skirt is a cable actuator.

3. The apparatus of claim 1 wherein said actuator means for selectively raising and lowering said apron is a pressure cylinder mounted to said apron and said apron skirt. 

1. In combination with a scraper excavating apparatus including a bowl having a cutting bit at the forwardmost terminal edge of its base wall and a suitably, vertically actuated apron, a secondary lip, comprising: an apron skirt being coextensive in width with and or substantially similar curvature as said scraper apron; guideways fastened at each side of said scraper apron to guide vertical travel of said apron skirt over the lower portion of the forward, exterior side of said apron; and an actuator means for selectively raising and lowering said apron skirt with respect to said apron, to dispose the lowermost terminal edge of said apron substantially, contiguously adjacent the uppermost side of said scraper cutting bit.
 2. The apparatus of claim 1 wherein said actuator means for selectively raising and lowering said apron skirt is a cable actuator.
 3. The apparatus of claim 1 wherein said actuator means for selectively raising and lowering said apron is a pressure cylinder mounted to said apron and said apron skirt. 